Resize error

I recently resized a RAID 5 GPT volume on a Highpoint RocketRAID system from 
4TB to 5TB, and now I need to resize the (single) contained partition and 
the ext2 fielsystem.  I tried gparted, but it overflows, saying it is going 
to "expand" the 3.64TiB partition to 561.19GiB.  I didn't execute the

command.  I tried parted, but when I try to resize the partition it gives me 
an error saying , "File system has an incompatible feature enabled." 
I can 
find multiple references to this error on the web, but none of them seem to 
relate or give a fix for the problem.  Using debugfs, I'm showing the 
enabled features are resize_inode, dir_index, filetype, sparse_super, and 
large_file.

Using tune2fs I could clear dir_index, filetype, or sparse_super features, 
if one of them is the problem, but I don't know which if any of them are the 
problem.  If I were to guess, I would think it would be the sparse_super 
option, but the last thing I want to do is guess.

I'm running Debian Etch on an AMD Athlon 64 x 2 processor under a 
2.6.18-6-amd64 kernel.